Rotary retort for the treatment of oil shale and the like



Nov. 10, 1931. T. M.' DAVIDSON ROTARY RETORT FOR THE TREATMENT OF OIL SHALE AND THE LIKE 6 Sheets-Shet Filed Oct. 29. 1930 Inventor J/l. 9W0! y AA 2 M Attorney 1931. T. M. DAVIDSON 1,831,704

ROTARY RETORT FOR THE TREATMENT OF OIL SHALE AND THE LIKE Filed Oct. 29. 1930 s Sheets-Sheet 2 Inventor Attorney.

Nov. 10, 1931. T. M. DAVIDSON ROTARY RETORT' FOR THE, TREATMENT OF OIL SHALE AND THE LIKE Filed Oct. 29, 1930 6 Sheets-Sheet 5 Inventor R ]/Z A fitornel T. M. DAVIDSON Nov. 10, 1931.

ROTARY RETORT FOR THE TREATMENT OF OIL SHALE AND THE LIKE Filed Oct. 29, 1930 6 Sheets-Sheet 5 Invento flttorney.

Nov. 10, 1931. T. M. DAVIDSON 1,831,704

ROTARY RETOBT FOR THE TREATMENT OF OIL SHALE AND THE LIKE Filed Oct. 29, 1930 6 Sheets-Sheet 6 J1 ttorlwy.

Patented Nov. 10, 1931 UNITED STATES PATENT, "OFFICE THOMAS MALCOLM DAVIDSON, OI" HATCH END, ENGLAND ROTARY REToRT roe THE TREATMENT or on; SHALE ANnTnn LIKE Appliflaflen filed October. 29., 1930, Serial No. 491,957, and in Great Britain ctoberi17 1 92 9.

ous separation of dust from the liberated va ours within the retort.

ccording to the invention, also, gastight joints are provided between the retort and the feed mechanism at the one end and the discharge chamber at the other end. Such joints are conveniently formed by providing concentrically disposed surfaces res ctively on the rotary retort and the fixed e ement and fitting in a channel or groove in one of the said surfaces a plurality of split rings in which splits are staggered and'which bear upon the other of the said surfaces and. which are maintained in close contact and against the side of the channel or groove a Y rubbing ring mounted in the channel or groove and applied against the split rings with pressure under the action of springs.

According to the invention, moreover, the gases and vapours of distillation are with drawn from the retort by an outlet tube extending a suitable distance into the retort corresponding to that part in which the process of distillation proceeds and advantageously disposed eccentrica-lly with refer ence to the axis of the retort.

According to the invention, moreover, there are provided reciprocating scrapers which have a relative movement in the circumferential direction with reference" to the According to the invention, moreover, the said reciprocating carrier may be disposed forward of the outlet tube withina fixed casing which may be of tubular construction, and which may also serve for the support of reciprocating scrapers mounted upon the said carrier. p

According to the invention, moreover, the said scraper carrier may be provided with auxiliary scraping devices adapted to ,maintain the interior of theoutlet tube and the casing of the scraper carrier free of "dust that may tend to, accumulate therein. According to, the invention, also, thejfeed end of the retort mayladvanta eously fbep'rovided with a water vapour'o take tube @dilsposed co-axially and extending through the feed mechanism to the exterior for connec tion to' a' conduit or the like whereby the water vapour may 'be withdrawn.

According to the invention, moreover, the

residue of distillation. may be utilized in the heating furnacetapplied' toth retort, andfor this purpose the residue maybe delivered from the discharge chamber by way vof apipe According to theinvention, moreover, the

said valves may be provided as power-actuated slide valves of a construction such that i when approaching the closed position they are moved in the direction of, and applied to, the respective seats with a pressure which increases with the forward movement 'ofi the valve.

The invention further comprises the details of construction which are hereinafter set forth. r p v p p A construction of retort and retort setting according tothe invention is illustrated in the accompanying diagrammatic drawings, by way of example. i

Figuresl (parts a and b) ,2,,3and 4 are respectively side elevation, plan, and elevations from opposite ends respectively of retort and setting,'partly in section in the first two-fig ures. Y

Figures 5 and 6' (parts 'aand b) are enlarged transverse and longitudinal sections of the retort.

Figures 7 and 8 are detail transverse sections of scrapers for freeing the vapour outlet tube of dust.

Figures 9 and 10 are sectional views of the gas tight joints provided at the respective ends of the retort, and

Figures 11, 12and 13 are corresponding sectional views of the residue outlet valves.

In carrying the invention into effect the rotary retort a is mounted within a corresponding cylindrical heating :chamber. 6 within a setting Z), at an inclination of, say, 1 in 120 downwards towards the discharge end at which is provided a heating furnace Z2 supplied with fuel by a mechanical stoking device 12 to which combustible gas may also be supplied by a supply pipe The heat ing gases pass upward from the furnace Z2 into one end of a longitudinal fine of disposed adjacent and parallel with the heating chamber 6 and transversely disposed ports 01. passages indicated in Figure 2 by centre lines are provided in the setting wall between the flue b and the chamber 5 which may be respectively coextensive, the flow of the heating gases through the ports or passages being controlled by vertical dampers, not shown. The control rods of the dampers may be ad justably secured to a longitudinally disposed angle member b according to the extent of opening of each damperjas' desired; while at the charging endthe chamber 5 communicates with a chimney b for the discharge of the waste heating gases. I Means may be provided to deliver the ash or residue through a discharge outlet at b disposed in a position beside the furnace and beneath the setting. V

The retort a may rotate upon bearing rings a supported by and between bearing rollers a at two orm'ore positions while at the dis charge end rollers a disposed upon axesnormal to the axis of the retort are provided to bear upon the adjacent bearing ring and to resist longitudinal thrust. The retort may be rotated by an electric motor through worm gear a, reduction gearing a and a toothed ring a mounted at the charging end of the retort.

For charging the retort there is provided a bunker 0 from which the charge of shale or the like is fed into a hopper thence into a stationary cylinder 0 within which is disposed a feed worm 0 mounted upon ahollow shaft. The feed worm is rotated by suitable gearing (not shown) to permit axial movement of the feed shaft for regulation of the feed, effected for example, by means of a hand-operated adjusting screw and nut, as at 0 At the feed end the retort is closed by a disc a (Figures 1 and 6) having a central aperture fitted with an outwardly extending cylindrical flange a (Figure 9), into which the feed cylinder 0 may extend, and a gastight fit is provided by a number of concentric split rings 0 fitting within the cylindrical flange a and confined between one shoulder or flange of a groove upon the exterior of the feed cylinder 0 and a rubbing ring a mounted upon the other shoulder or flange of the groove by means of a number of pins 0 supported in equi-distant positions upon the rubbing ring which are received into corresponding holes provided in determined .position parallelw'ith the axis of the cylinder and formed in the said shoulder, the rubbing ring-c being maintained in contact with the split rings 0? by the helical springs 0 compressed by screw-threaded plugs 0 inserted within the said shoulder or flange from the outer side. p l

The stationary discharge casing (Z (F igure 6) is of a diameter corresponding with that of, the retort, and a gas-tight joint is similarly made between the retort and the casing (l. Thus, the casing cl has an integral annular flange (Z (Figure 10) carrying a ring (Z of Tcross-s'ection to form a cylindrical surface to support a number of concentric split rings 6 which are confined between a flange 6 upon a ring 6 secured by a second flange e to an integral annular end flange a of the retort a. A rubbing ring 6 is disaosed between the flange 0 and the split rings and is maintained in contact by helical springs a seated within holes formed in the said flange and upon pins 6', set in equi-distant positions upon the ring 6. Upon the flange 6 of the ring 6 a plate 6 is provided to extend to a position near the peripheral wall of the casing d. By such means it will be understood that relative movement is possible between the cylinder 0 and the cylindrical flange a as well as between the end of the retort a and the stationary casing (Z for the accommodation of extension and contraction of the retort, and that by means of the ring 6 an annular space is provided to surround the vapouroutlet pipe It so that thus in the rotation of the retort a the charge on passing through the stationary feed cylinder 0 passes into the charging end of theretort and in the rotation of the retort in the direction of the arrow (Fignrefi) the charge lies substantially in the position indicated by the line m in that figure, and thus owing to the downward inclination of the retort the charge eventually finds its waythrough the ring 0 into the stationary cylinder cl whence it passes through the discharge outlet pipe f. The i 'aponrs produced pass through the bearing ring is and into the tubular casing y and the outlet pipe ,h through an aperture 7?, the vapour also passing through the bearing ring to theouter end of the vapour outlet tube It through to the vapour ofi'take fitting. (P.

The discharge pipe f is provided with dumaxim plieaterdischurgevva'ilveey (Figures 1l-to'f-13-) leading; to the: discharge chamber beside the furnace b Eacln of the sai-d' -valves: com- 1 prises a? substantially rectangular casing f horizontally l'disposed and extending ilaterally of-the said iaeor conduit. A valve sea-tin l r:

connection to mechanical or; hydraulic ope-1v ating geara In orderthat the valves-unity move freely from theseats and at: the same time be pressed firmly thereon in the-closed position, the ends of-the opera-ting rods f are extended beyond the point of engagement with the valve, and the extremity is formed with an inclined surface on the lower side, which when: the valve arrives at the positionof. closure engagesra corresponding inclinedsurface formed=onalug 7" provided upon the wall of .the casing-in: su'clrmanner that? the operating rodis-ca-usedv to rise; and thus to 1 applythe valve with pressure irpon theseate. The connection ofthe valvewith the operatingwrod .isconven-iently-effected by providing-.the'rod with. a screw-threaded portion 1 which is disposed loosely within coincident borings provided in arpair otlues f on the underside of the valveandwhich is engaged by a nut or screwed collar f disbetween-the said lugs and. *torming the means for. tran-sferring the movement of the rod toithevalve. v 7

The discharge 1 pipe or conduit; 7' the point beyond the discharge-valves issuit ably connected toa stokcr-bunker y, (Figures c 1 and 4) disposedinacon-ven-icnt position with reference to the mechanical stoker; provided in the furnace.

The gas or vapour outlettubeh (Figures 5 and 6) is conveniently provided otacrosssection-Which approximates to a. semicircle with a rectangular extension onthe outer side of the diameter; The'caxis of the tube represented by: the centre of thesemi-c-ircle is advantagueousl-y disposed vertically above the axis of the retortc; and the diameter is inclined to the vertical through an angle of, say,15 more or lessin the directionvopposi-te to that of the rotation of thehretort and so that-the flat side is disposed to that side of the retort where. the charge tends-to gather. At the dischargeendthetube is fitted with a fiangeor plate lr 'bywhich it is mounted in position upon the" interior of the end wall of the discharge chamber (l,- which atthe exterior isprovided with-anon trally disposed 'vapour 'ofltake fitting di which maybe; provided 1 with a controlling valve, and is advantageously; connected .to a

dust collector by which idustmay be extracted from the discharge gases and "vapours; The

cross-section ofythe gas or vapour" outlet tube I adjacent .thev'flange: on plate h is advantageously modified to provide an easy passage: for the gases: to? the centrally I disposed 'oittakewfitting; (l The vapour outlet tube advantageously extends into the retortato a distance ofi-approximately half the length of the retort; where itis supported by a; hollow cylindrical bearing or fitting.i'rotatably fitted within a supporting spider a mounted within itheiretortr the. end of'the outlet tube being suitably closed: andifitted for connection to the saidfbearing; Forward of thegas or vapour-outlet tube and extendingtwo-thirds of the remaining: part of thelengthof the retort, there is provided a tubular casing j otra' cross-section corresponding with that of the hearingsz' with which it is conveniently engaged: by; means: :of dog teeth 9'. engaging corresponding recesses wformedzin the adja+ contend of: the beaiingrz'iandfby'means of a flange: j which is engaged with a: screwed flange. or: collar:- z' fitted on the exterior of u the bearing: At the forward end the-tubular casing jxis provided with a flange: 4' 1" f01811- gag-ement with "a similar bearing; k l which again: is rotatably supportedfwfithin a spider a: secured to therretort,

The gas; or vapournoutlet tube which is situated eccentrically 1 in. relation" tothe re tort isrprovide'd in'J-the-lowermost portion thereof withga'swofi'take opening 101'- slotz h at about 20 "feetifrorri the discharge end or a-sdistance 2 from the discharge .end equal to approximatelyone third of the total length of the retort. The lowermost portion of the' flatz face of the 'vapourzoutletl tube iszadvantageously strengthenedihy means of a bar or' strip: Jr" of metal extending the full length of the: tube and welded theretoe The flat portion ofthe' vapour: outlet: tubeis further advantageously extended upward from the forward end and for the greater vpart 1 of 1 its length at hi to'form a supporting member for the: scrapers which are" applied'to the inner face: ofithe retort. The upperjedgeliof the: said extension is strengthened on the outeinsidebymeansof a length-0f strip metal k extending-the tull: length of the: extension. The tubular casingj is similarly provided with an upwardly extending extension? or plate j inwline with that of the'gas' orvapour outlet. tube 'fllld extending; inficonform'ity I mounted upon :the upper edges: of 1 tlre'rexten sions of the: -va pour outlet tube and the tubu lar. casmg .j, and ;-comprisea=respectively lengths of plating that are formed to a U the upper edge of the said extensions with a rear-wardly and downwardly projecting portion Z inclining towards the said outlet tube and tubular casing. At intervals along the length of the said plates there are mounted,

by means of screws, rivets or bolts, the scrapers m, each comprising a body of a form to fit upon the upper surface of the carrying plate Z and having a blade m extending upwardly and forwardly for engagement with the inner surface of the retort, with which it forms an obtuse angle, the body being substantially of plate form with the blade extending therefrom in the form of a web, and the rearmost portion of the body being advantageously cut or formed to an angular point which is received upon the rearwardly extending portion of the carrying plate.

Each of the scraper-carrying plates Z is adapted to be reciprocated along the extension of the outlet tube 72, or of the tubular casing j by means of a rectangular plate member a which is disposed to the rear of the said extensions and extends, in a direction nearly parallel to the fiat sides of the said tube and casing, into the outlet tube or tubular casing through a suitable slot, as at M, in the upper surface of a sufficient length to permit the necessary reciprocation of the said plate. The upper edge of the plate 0?. is bent or formed rearwardly, as at W to an inclination corresponding with the downward inclination of the scraper-carrying plate Z to which the plate member is secured by bolts or rivets.

For effecting the reciprocation of the scrapers there is carried upon the lower face of the outlet tube and the tubular casing, a rod 0 which is reciprocated by suitable mechanism, disposed at the feed end of the retort. This rod has welded to it at suitable positions radially disposed web or fin plates 0 comprising a length of strip metal mounted upon a U-shaped saddle adapted to fit upon the rod. The said web plates are adapted to be engaged by the plate members 1?. before referred to and for the purpose the lower edges of the plate member a are thickened, at 42 as by the welding of a second thickness of material thereto, forthe formation of a recess or pocket into which the web plate 0 before referred to may be received.

The reciprocating rod 0 further serves to carry a series of scraper devices adapted in the reciprocation of the rod to move over the lower surface of the vapour outlet tube and the tubular casing respectively. Each of such scraper devices conveniently comprises a saddle p welded to the rod 0 and having at one end an upstanding lug to which is pivoted a scraping blade 7) or blades extending transversely and having the lower edges conforming in shape to the curvature of the lower inner surface of the outlet tube or tubular casing. Such scrapers of such form are piv oted upon the said lugs in such manner as to be capable of swinging in the axialdirection of the rod in its movement in the one direction, and thus to pass over the dust or the like lar casing or-through orifices intermediate the said ends. They may be adapted to feed the dust all in one direction or some in one direction and some in the other direction. At the forward end of the rod 0, which projects beyond the forward bearing is at the forward end of the tubular casing, there is mounted a block 0 by which a connection may be made with an operating rod 9 axially disposed with reference to the retort and extending out wardly through the hollow shaft of the feed worm 0 The said block is conveniently mounted in positionupon the reciprocating rod 0 by the formation of flats upon the rod which engage corresponding surfaces in a U-shaped recess in the bottom of the block, the block being secured in position by means of a bolt'or set screw 0 while connection with the operating rod may be effected by a screwthread provided upon the rod which engages a screw-threaded bore in the block.

The operating rod 9 is extended sufficiently beyond the hollow shaft of the feed mechanism to permit its reciprocation to the extent necessary for the reciprocation of the scrapers. It is connected by such means asa cross head g (Figures 1 and 2) to a frame g having two downwardly extending arms or supports Q3, at the lower ends of which are provided nuts or clamps secured to a screw threaded rod or shaft 1 adapted to be engaged with a nut in the form of a pinion or the like contained in a casing s and that is rotated by such means as a worm drive 8. Such drive receives movement from a shaft 8 which is driven through two fixed pulleys and a loose pulley by way of a crossed and an open belt from a suitable driving shaft t. WVhen the operating rod g has been advanced to the end of its travel in one direction, the direction of rotation of the worm gear is reversed automatically by such means as a tripping mechanism 8 serving to throw over the driving belts and actuated, for example, by one of the arms or supports 9 It will be understood that the invention is not limited to the particular details of construction which are hereinbefore described,

since these are given merely by way of illustration and are subject to variation according to the requirements of particular applications of the invention. It is, however, es-

sential that in all'constructions of the scraping mechanism the scrapers should be of a form such that the operative edge or surface forms an obtuse angle with the surface of the retort so that the deposit upon the surface is removed in a manner similar to. that which applies in the use of a tool for cutting metal.

I claim:

1. A cylindrical retort mounted for rotation about its axis, a gas and vapor outlet tube mounted within said retort and fixed against rotation therewith, said vapor outlet tube being longitudinally slotted and having a flattened portion extending adjacent the slot and longitudinally of said retort, scraper blades adapted to engage the inner surface of said retort having guiding means slidably engaging the flattened portion of said vapor outlet tube, and means for reciprocating said scraper blades on said flattened surface longitudinally of said retort comprising a member mounted to reciprocate within said vapor outlet tube and having a carrier for the blades extending through the slot in said tube.

2. A retort according to claim 1, comprising a series of scraper devices mounted within the gas and vapor outlet tube and adapted to engage the inner surface thereof, and means operatively connecting said scraper devices to the member mounted to reciprocate within said tube.

3. A rotary retort for the treatment of oil shale and other solid carbonaceous sub stances, comprising a tubular body mounted as for rotation about its axis, a stationary feed mechanism therefor at one end of said body, a stationary discharge chamber for said tubular body at the other end of said body, the feed mechanism and discharge chamber 0 making gas tight joints with the said body, a gas and vapor outlet tube mounted within said retort and fixed against rotation therewith, said vapor outlet tube being longitudinally slotted and having a flattened portion extending adjacent the slot and longitudinally of said retort, scraper blades adapted to engage the inner surface of said retort having guidlng means slidably engaging the flattened portion of said vapor outlet tube, and

means for reciprocating said scraper blades on the flattened portion of said outlet tube longitudinally of said tubular body, comprising a member mounted to reciprocate within sald vapor outlet tube and having a carrier for the blades extending through the slot in said tube.

THOMAS MALCOLM DAVIDSON. 

